In general, a vacuum cleaner is a device that sucks dust and dirt on surfaces to be cleaned, using a suction motor in the main body, and then filters the dust and dirt in the main body.
Vacuum cleaners can be classified into an upright vacuum cleaner in which a suction nozzle is connected to the main body to be moved with the main body and a canister vacuum cleaner in which a suction nozzle is connected to the main body through an extension, a handle, and a hose, etc.
An “active type driving vacuum cleaner” has been disclosed in Korean Patent NO. 10-0876696 in the related art. The cleaner in this prior art document controls its body by sensing operation by a user through the speed (or acceleration) at a specific position or the relative speed (or relative acceleration) between two specific positions in the body.
The cleaner in the prior art document includes: a body having a rotational center; wheels for moving the body; a driving unit for operating the wheels, a suction hose coupler coupled to the body at a predetermined distance from the rotational center; at least one sensor sensing the movement speed of the rotational center through movement of the suction hose coupler; and a controller controlling the driving unit on the basis of sensing information from the sensor.
In detail, according to the active type driving vacuum cleaner in the prior art document, when the body inclines forward, the inclination is sensed and the driving unit is controlled such that the body moves forward, whereby the cleaner automatically follows movement of a user. Accordingly, the main body has to incline in order to automatically follow movement of a user.
However, several parts including a suction motor are disposed in the main body of cleaners, so the weight is increased and the moment of inertia is accordingly large. Accordingly, a user has to apply relatively large force to incline the body of cleaners and it is difficult to follow fine movement of a user.
Further, according to the active type driving vacuum cleaner in the prior art document, the main body may incline and move forward regardless of user's intention, for example, due to twist of the suction hose.
Further, according to the active type driving vacuum cleaner in the prior art document, when a user moves back, the main body may excessive incline and fall down.